Equations 1112
Sunday, April 26, 2015
3:15 PM
Final Review Page 1
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Example 1
Sunday, April 26, 2015
2:39 PM
Four point charges with magnitude 5.0 µC are placed at the corners of a square that is
30 cm on a side. Two charges, diagonally opposite each other, are positive, and the other
two are negative. What are the magnitude and the direction of the force on one of the
charges?
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Example 2
Sunday, April 26, 2015
2:46 PM
What are the 3 currents?
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Example 3
Sunday, April 26, 2015
2:49 PM
Although the evidence is weak, there has been concern in recent years over
possible health effects from the magnetic fields generated by transmission lines. A
typical high-voltage transmission line is 20 m off the ground and carries a current
of 200 A. Estimate the magnetic field strength on the ground underneath such a
line. What percentage of the earth 's magnetic field does this represent?
Final Review Page 5
Example 4
Sunday, April 26, 2015
3:00 PM
Early black-and-white television sets used an electron beam to draw a picture on the
screen. The electrons in the beam were accelerated by a voltage of 3.0 kV; the beam was
then steered to different points on the screen by coils of wire that produced a magnetic
field of up to 0.65 T.
a)What is the speed of electrons in the beam?
b)What acceleration do they experience due to the magnetic field, assuming that it is
perpendicular to their path? What is this acceleration in units of g?
c)If the electrons were to complete a full circular orbit, what would be the radius?
Final Review Page 6